Unit 4: Further Mechanics, Circular Motion

Angular displacement, θ is how large an angle (in radians) has been rotated through from the origin.

Angular velocity, ω gives us the rate of rotation. It tells us how large an angle is moved through per second. Measured in rad/s.

• Angular velocity= 2π radians/time period= 2π/T 

We can also define angular velocity in terms of frequency, f

• ω= 2πf

Linear velocity, υ how quickly a rotating object travels in terms of distance, not angle. Measured in m/s.

•   υ= 2πr/T= 2πrf 
•  NB. because linear velocity=angular velocity x radius, υ= ωr and…